Core for molding concrete



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CORE FOR MOLDING CONCRETE Filed May 2l, 1934 atentecl Jan. 28, 1936 UETED STATES PATENT OFFICE 4 Claims.

This invention relates to form ties for use in connection with the forms employed in the construction cf concrete walls, and has reference more particularly to cores for molding sockets in the sides of the Wall around the tie-rods, which sockets are later filled with concrete plugs.

Concrete walls are usually constructed. in Wooden forms which are held rigidly in place against spreading and inward displacement by form ties.

One type of form tie consists of a single piece of flat metal band or round rod which extends through the form and which is provided with clamps on its ends for engaging the outer faces of the form. With this type, after the concrete has set and the form sides are dismantled, the projecting ends of the tie bands are cut oi and the central portion of each band remains embedded in the concrete.

Another type of form tie in common use comprises an intermediate tie rod and a pair of end bolts aligned axially and connected together by couplings of various kinds. With this type of tie, the intermediate rod is left embedded in the con- 25 crete and the end bolts are removed when the form is dismantled. With such type of tie, it is necessary to carry in stock a large number of the intermediate tie rods of diierent lengths because the walls vary greatly in thickness.

With both types of form tie, no part of the embedded metal should be exposed when the Wall is finished because, if any of the metal is exposed, it will rust and may stain the outer faces of the wall. For this reason, form ties are usually pro- 35 vided with removable core members adapted to form sockets in the outer faces of the Wall, which may be plugged with concrete for concealing the embedded metal parts after the cores have been removed and the ends of the ties have been cut off 40 or otherwise removed. One type of removable core is described in Letters Patent No. 1,950,018 issued March 6, 1934, to my assignee, Universal Form Clamp Co.

Many of the cores heretofore in use were of 45 conical shape. Such cores are not entirely satisfactory because they mold conical sockets from which the plugs of concrete are easily removed.

To be successful, the core members should be shaped so that the concrete surrounding the 50 socket formed by the core will have a mechanical bond with the plug to prevent loosening or falling out of the plug.

The main objects of this invention are to provide an improved form of core which will mold a 55 socket with which the inserted plug may have a mechanical bond so as to positively secure the plug against withdrawal; to provide a core of this kind which can be easily removed from the concrete when the form is dismantled and which may be used many times over; to provide improved means for detachably securing the core on the tie rod, and to provide an improved form tie of this kind which can be readily assembled on the form even by unskilled labor.

An illustrative embodiment of this invention is shown in the accompanying drawing whereinz Fig. 1 is a fragmentary transverse Vertical section of a wall form and wall, showing my improved core applied to a form tie of the rod type.

Fig. 2 is a longitudinal axial section of the core and core spreader.

Fig. 3 is a longitudinal axial section of the core and spreader, showing the same applied to a wall of the form and the core expanded or spread.

Fig. 4 is a fragmentary section of the socket in the concrete wall from which the core and spreader have been withdrawn.

Fig. 5 is an end elevation of the parts shown in Fig. 3, viewed on the line 5 5 of Fig. 3.

Fig. 6 is a section on the line 6 6 of Fig. 3.

Fig. 7 is an end elevation of the parts shown in Fig. 3, viewed on the line L-'I of Fig. 3.

In the construction shown, the improved tie is applied to a Wall form comprising the usual form sheathing IIB, studs I I, and wales I2. Since both ends of the form ties are or may be substantially identical, a description of one will suiiice for both.

The tie comprises a tie rod I3 which, it will be noted, is of a length sufficient to extend entirely across the form, with its ends projecting slightly beyond the outer sides of the wales I2. I4 designates the core member or insert, the purpose of which is to mold a recess or socket in the side of the concrete wall C, which recess or socket is later to be lled by a concrete plug to cover and conceal the portion of the tie rod that is allowed to remain in the concrete. In the form herein shown, this core member Id consists of a hollow rubber cylinder that is axially bored for mounting on the tie rod I3. When such a cylinder is compressed endwise, its intermediate portion will spread or expand, converting the cylinder into a general barrel-shape, as shown in Fig. 3. Both ends of the core are preferably countersunk, as shown, 'thereby producing on one end of the cylinder an annular ange I5 which functions as a seal in association with a sheathing Wall II] of the form in the manner and for a purpose later described.

I6 designates an inner clamp member that is formed With a tubular shank I1 slidable on the tie rod I3, the clamp head I6 tting a correspondingly shaped countersink in the inner end of the core. I8 designates a cooperating clamp plate that is likewise formed with a hollow shank I9 slidably mounted on the tie rod I3, the azi-,amp head I8 entering a shallow cup-shaped washer 2U that ts the countersink in the outer end ei" the core, its periphery constituting a support for the flange I5 to'prevent inward collapse of the latter under compression. As shown in Figs. 2 and 3, the shank I9 is internally threaded at 2| to receive a correspondingly threaded end 22 of the shank Il', so that, under relative rotation of the two clamps, they may be drawn togetherV thereby exerting endwise compression on the elastic co-re I4 causing the latter to spread or bulge radially in the manner clearly shown Fig. 3;

In a thickened outer endportion of the shank 'I9 is formed a transverse hole 23 adapted te re` Vceive a cut nail 25 by which: the shank I9 and its clamp plate I8 may be fastened to the tie rod I3.

In the practical useY of the device, holes 25 slightly larger than the shank IS are drilled through the sheathing I0, the tie rod I3 is started through the same,zand thetwo previously compressed and expanded cores Ill are slipped on the rod insidethe form. 'I'he shanks I9 are brought through the sheathing I and fastened to the tie rod by thecut nails 24. The rod clamps 26 (Fig. lfare applied to the projecting ends of the tie roel, and, before the 'concrete is poured, thefcores are pressed tightly against the sheathing tocompress the flange Inand thus form a seal te prevent grout seepage.Y This may be done either by giving the core one or tWQ turns by handwor by applying clamps outside the Wales I2 and thus. tightly drawing the side walls I5"V of the form against the flanges I5 of the cores.

When the forms have been removed, the shank I9 is given a few backward turns, which releases 'the compression on the core cylinder, and the latter automatically returns to its original cylindrical shape (Fig. 2), so that itcan be readily withdrawn from the cavity 2l (Fig. 4) formed thereby, ready for an almost unlimited number of 're-uses. It may here be noted that there is practically no bond between concrete and rubber.

YThe rod I3 is then cut off by a suitable tool at er near the inner end of the cavity 21, and the latter is then filled with grout, the bulging or narrel-shaped recess mechanically retaining the Telug. Y l

e It will be understood that structuralVY details shown and described may be altered or omitted without departing from the spirit of therinvention as defined by the following ciaims.

I claim: i

1. A device of the class described for molding concrete, comprising a form tie rod, a radially eX- pansible and endwise compressible core of resilient material mounted onsaid tie rod, and means for compressing said cere endwise comprising clamp plates engaging the ends of said 'core and provided with relatively otatable shank portions having threadedengagement with each other, one of said shank portions extending through said core.

2. A device of ithe class described for molding concrete, comprising a form tie rod, a radially ex-V pansible and endwise compressible core of resil-Y ient material mounted on said tie rod, and meansY for compressingVY said core endwise comprising clamp piates engaging the ends of said core and provided Vwith relatively rotatable hollow shank portions mounted on said tie rod andfV having threaded engagement with veach other.

3. A device of the class described for Vinolding concrete, comprising a form tie rod, a cylindrical 4. A device of the class described for molding' concrete, comprising a ferm tie rod, a cylindrical resilient rubber Vcore formed with an annular flange on one end thereof and mounted Von said tie rod, 'clamp plates engaged with the ends of said core and provided with relatively rotatable hollow shank pertions mounted on said tie rod and having threaded engagement with each other, and a nail extending across one of said shank portions in fastening engagement with said tie rod.

f MACGREGOR Sf ANDERSON. 

